Towards Reactive Electrochemical Transport Using the Lattice Boltzmann Method. Part II: Atomistically Informed Non-Ideal Species Transport
Year: 2026
Type: preprint
Abstract: The lattice Boltzmann method (LBM) provides an efficient framework for simulating species transport in electrochemical systems; however, conventional formulations commonly rely on ideal or dilute-solution descriptions that neglect molecular-scale non-idealities near solid–electrolyte interfaces. In this work, we extend our previously developed LBM formulation to incorporate non-ideal thermodynamic contributions through the excess chemical potential. The resulting formulation retains the original kinetic structure of the LBM, with non-ideal effects introduced through a modified source term in the species transport equation. This treatment provides a general thermodynamic closure through which steric interactions, species-specific interfacial free energies, and, more generally, excess free-energy models can be incorporated within the same transport framework. The formulation is demonstrated for the electrical double layer by progressively introducing finite-size effects and species-specific microscopic interfacial free-energy contributions. The results show that steric interactions substantially limit the large interfacial ion concentrations predicted by the classical point-ion Poisson–Boltzmann description, while microscopic free-energy contributions produce a further reorganization of the ionic distributions and, consequently, of the interfacial charge density and electrostatic potential. Using hypothetical short-ranged free-energy profiles, the calculations further demonstrate that molecular-scale thermodynamic information can generate an electrostatic response extending beyond the spatial range of the microscopic input through the self-consistent redistribution of charge. The present formulation therefore establishes the excess chemical potential as a natural bridge between microscopic interfacial thermodynamics and mesoscopic species transport. Although analytical free-energy profiles are employed here for demonstration, the framework is not restricted to a particular functional form and permits the direct incorporation of speciesspecific free-energy information obtained from molecular or atomistic simulations, providing a route toward atomistically informed LBM simulations of electrochemical transport.
Source: ChemRxiv
Authors: Ebrahim Tayyebi, Kai S. Exner, ebrahim tayyebi
Institution: University of Duisburg-Essen
Language: English
Subfield: Computational Mechanics
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Funder: Deutsche Forschungsgemeinschaft
OpenAlex ID: W7211918198